Influence of shear flow on polymorphic behavior and microstructural development during palm oil crystallization

The influence of shear on the crystallization of palm oil was studied at four different crystallization temperatures (18, 20, 22 and 25 degrees C). Time-resolved X-ray analyses were carried out to study the effect of continuous shear on the crystallization kinetics of the fat. Rheological measurements were used to assess the effect of a shear step on crystallization, and finally polarized light microscopy was used to follow changes in microstructure due to the applied initial shear step. It was shown that shear enhanced the primary crystallization, even when low shear rates were applied for a short period. Furthermore, a shear step prior to crystallization without shear has a marked influence on the microstructural development